1. Field of the Invention
The present invention relates to an intake manifold.
2. Description of Related Art
An intake manifold is typically produced by integrating resin-molded pieces. For example, an ultrasonic vibration welding is used for the integrating. FIGS. 5, 6A, 6B, 7, and 8 show an intake manifold 100 for sending intake air into a four-cylindered engine 110. The intake manifold 100 is produced by welding four pieces 101.
Here, a traverse engine is traversely mounted on a front engine front drive (FF) type automobile such that cylinders of the engine are arranged in a width direction of the automobile. In the traverse engine, the intake manifold 100 is disposed such that intake ports 102 communicating with the cylinders are also arranged in the width direction of the automobile.
As shown in FIG. 8, a fuel system having an injector 103 and a fuel rail 104 is located above the intake manifold 100. The injector 103 injects fuel, and the fuel rail 104 distributes fuel into the injector 103. If the intake manifold 100 is broken due to a large impact to the automobile, a part of broken intake manifold may contact the fuel system. In this case, the fuel system may be damaged.
JP-A-2003-322059 discloses an intake manifold 100 shown in FIG. 9, in which a welded part 105 of the intake manifold 100 is located above a fuel system. The welded part 105 is the most breakable part of the intake manifold 100.
As shown in FIG. 9, the intake manifold 100 includes a connector 106 to be connected to an engine. Further, a first piece 101a welded to a second piece 101b is improved such that the welded part 105 defined between the first piece 101a and the second piece 101b is located above the fuel system. That is, the connector 106 of the first piece 101a is made to have a linear shape, to be relatively long, and to be inclined downward. Thus, the welded part 105 is located above the fuel system.
However, the connector 106 may not be able to be long or inclined, based on mounting conditions of a variety of devices in an engine compartment. In this case, the welded part 105 may be required to be located under the fuel system. Further, the fuel system is required to be protected from a broken piece of the welded part 105, if the welded part 105 is broken.